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1 /*
2  * Copyright © 2014 Intel Corporation
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining a
5  * copy of this software and associated documentation files (the "Software"),
6  * to deal in the Software without restriction, including without limitation
7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8  * and/or sell copies of the Software, and to permit persons to whom the
9  * Software is furnished to do so, subject to the following conditions:
10  *
11  * The above copyright notice and this permission notice (including the next
12  * paragraph) shall be included in all copies or substantial portions of the
13  * Software.
14  *
15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
21  * IN THE SOFTWARE.
22  */
23 
24 #include "brw_nir.h"
25 #include "brw_nir_rt.h"
26 #include "brw_shader.h"
27 #include "dev/intel_debug.h"
28 #include "compiler/glsl_types.h"
29 #include "compiler/nir/nir_builder.h"
30 #include "util/u_math.h"
31 
32 static bool
remap_tess_levels(nir_builder * b,nir_intrinsic_instr * intr,enum tess_primitive_mode _primitive_mode)33 remap_tess_levels(nir_builder *b, nir_intrinsic_instr *intr,
34                   enum tess_primitive_mode _primitive_mode)
35 {
36    const int location = nir_intrinsic_base(intr);
37    const unsigned component = nir_intrinsic_component(intr);
38    bool out_of_bounds;
39 
40    if (location == VARYING_SLOT_TESS_LEVEL_INNER) {
41       switch (_primitive_mode) {
42       case TESS_PRIMITIVE_QUADS:
43          /* gl_TessLevelInner[0..1] lives at DWords 3-2 (reversed). */
44          nir_intrinsic_set_base(intr, 0);
45          nir_intrinsic_set_component(intr, 3 - component);
46          out_of_bounds = false;
47          break;
48       case TESS_PRIMITIVE_TRIANGLES:
49          /* gl_TessLevelInner[0] lives at DWord 4. */
50          nir_intrinsic_set_base(intr, 1);
51          out_of_bounds = component > 0;
52          break;
53       case TESS_PRIMITIVE_ISOLINES:
54          out_of_bounds = true;
55          break;
56       default:
57          unreachable("Bogus tessellation domain");
58       }
59    } else if (location == VARYING_SLOT_TESS_LEVEL_OUTER) {
60       if (_primitive_mode == TESS_PRIMITIVE_ISOLINES) {
61          /* gl_TessLevelOuter[0..1] lives at DWords 6-7 (in order). */
62          nir_intrinsic_set_base(intr, 1);
63          nir_intrinsic_set_component(intr, 2 + nir_intrinsic_component(intr));
64          out_of_bounds = component > 1;
65       } else {
66          /* Triangles use DWords 7-5 (reversed); Quads use 7-4 (reversed) */
67          nir_intrinsic_set_base(intr, 1);
68          nir_intrinsic_set_component(intr, 3 - nir_intrinsic_component(intr));
69          out_of_bounds = component == 3 && _primitive_mode == TESS_PRIMITIVE_TRIANGLES;
70       }
71    } else {
72       return false;
73    }
74 
75    if (out_of_bounds) {
76       if (nir_intrinsic_infos[intr->intrinsic].has_dest) {
77          b->cursor = nir_before_instr(&intr->instr);
78          nir_ssa_def *undef = nir_ssa_undef(b, 1, 32);
79          nir_ssa_def_rewrite_uses(&intr->dest.ssa, undef);
80       }
81       nir_instr_remove(&intr->instr);
82    }
83 
84    return true;
85 }
86 
87 static bool
is_input(nir_intrinsic_instr * intrin)88 is_input(nir_intrinsic_instr *intrin)
89 {
90    return intrin->intrinsic == nir_intrinsic_load_input ||
91           intrin->intrinsic == nir_intrinsic_load_per_vertex_input ||
92           intrin->intrinsic == nir_intrinsic_load_interpolated_input;
93 }
94 
95 static bool
is_output(nir_intrinsic_instr * intrin)96 is_output(nir_intrinsic_instr *intrin)
97 {
98    return intrin->intrinsic == nir_intrinsic_load_output ||
99           intrin->intrinsic == nir_intrinsic_load_per_vertex_output ||
100           intrin->intrinsic == nir_intrinsic_store_output ||
101           intrin->intrinsic == nir_intrinsic_store_per_vertex_output;
102 }
103 
104 
105 static bool
remap_patch_urb_offsets(nir_block * block,nir_builder * b,const struct brw_vue_map * vue_map,enum tess_primitive_mode tes_primitive_mode)106 remap_patch_urb_offsets(nir_block *block, nir_builder *b,
107                         const struct brw_vue_map *vue_map,
108                         enum tess_primitive_mode tes_primitive_mode)
109 {
110    const bool is_passthrough_tcs = b->shader->info.name &&
111       strcmp(b->shader->info.name, "passthrough TCS") == 0;
112 
113    nir_foreach_instr_safe(instr, block) {
114       if (instr->type != nir_instr_type_intrinsic)
115          continue;
116 
117       nir_intrinsic_instr *intrin = nir_instr_as_intrinsic(instr);
118 
119       gl_shader_stage stage = b->shader->info.stage;
120 
121       if ((stage == MESA_SHADER_TESS_CTRL && is_output(intrin)) ||
122           (stage == MESA_SHADER_TESS_EVAL && is_input(intrin))) {
123 
124          if (!is_passthrough_tcs &&
125              remap_tess_levels(b, intrin, tes_primitive_mode))
126             continue;
127 
128          int vue_slot = vue_map->varying_to_slot[intrin->const_index[0]];
129          assert(vue_slot != -1);
130          intrin->const_index[0] = vue_slot;
131 
132          nir_src *vertex = nir_get_io_arrayed_index_src(intrin);
133          if (vertex) {
134             if (nir_src_is_const(*vertex)) {
135                intrin->const_index[0] += nir_src_as_uint(*vertex) *
136                                          vue_map->num_per_vertex_slots;
137             } else {
138                b->cursor = nir_before_instr(&intrin->instr);
139 
140                /* Multiply by the number of per-vertex slots. */
141                nir_ssa_def *vertex_offset =
142                   nir_imul(b,
143                            nir_ssa_for_src(b, *vertex, 1),
144                            nir_imm_int(b,
145                                        vue_map->num_per_vertex_slots));
146 
147                /* Add it to the existing offset */
148                nir_src *offset = nir_get_io_offset_src(intrin);
149                nir_ssa_def *total_offset =
150                   nir_iadd(b, vertex_offset,
151                            nir_ssa_for_src(b, *offset, 1));
152 
153                nir_instr_rewrite_src(&intrin->instr, offset,
154                                      nir_src_for_ssa(total_offset));
155             }
156          }
157       }
158    }
159    return true;
160 }
161 
162 void
brw_nir_lower_vs_inputs(nir_shader * nir,bool edgeflag_is_last,const uint8_t * vs_attrib_wa_flags)163 brw_nir_lower_vs_inputs(nir_shader *nir,
164                         bool edgeflag_is_last,
165                         const uint8_t *vs_attrib_wa_flags)
166 {
167    /* Start with the location of the variable's base. */
168    nir_foreach_shader_in_variable(var, nir)
169       var->data.driver_location = var->data.location;
170 
171    /* Now use nir_lower_io to walk dereference chains.  Attribute arrays are
172     * loaded as one vec4 or dvec4 per element (or matrix column), depending on
173     * whether it is a double-precision type or not.
174     */
175    nir_lower_io(nir, nir_var_shader_in, type_size_vec4,
176                 nir_lower_io_lower_64bit_to_32);
177 
178    /* This pass needs actual constants */
179    nir_opt_constant_folding(nir);
180 
181    nir_io_add_const_offset_to_base(nir, nir_var_shader_in);
182 
183    brw_nir_apply_attribute_workarounds(nir, vs_attrib_wa_flags);
184 
185    /* The last step is to remap VERT_ATTRIB_* to actual registers */
186 
187    /* Whether or not we have any system generated values.  gl_DrawID is not
188     * included here as it lives in its own vec4.
189     */
190    const bool has_sgvs =
191       BITSET_TEST(nir->info.system_values_read, SYSTEM_VALUE_FIRST_VERTEX) ||
192       BITSET_TEST(nir->info.system_values_read, SYSTEM_VALUE_BASE_INSTANCE) ||
193       BITSET_TEST(nir->info.system_values_read, SYSTEM_VALUE_VERTEX_ID_ZERO_BASE) ||
194       BITSET_TEST(nir->info.system_values_read, SYSTEM_VALUE_INSTANCE_ID);
195 
196    const unsigned num_inputs = util_bitcount64(nir->info.inputs_read);
197 
198    nir_foreach_function(function, nir) {
199       if (!function->impl)
200          continue;
201 
202       nir_builder b;
203       nir_builder_init(&b, function->impl);
204 
205       nir_foreach_block(block, function->impl) {
206          nir_foreach_instr_safe(instr, block) {
207             if (instr->type != nir_instr_type_intrinsic)
208                continue;
209 
210             nir_intrinsic_instr *intrin = nir_instr_as_intrinsic(instr);
211 
212             switch (intrin->intrinsic) {
213             case nir_intrinsic_load_first_vertex:
214             case nir_intrinsic_load_base_instance:
215             case nir_intrinsic_load_vertex_id_zero_base:
216             case nir_intrinsic_load_instance_id:
217             case nir_intrinsic_load_is_indexed_draw:
218             case nir_intrinsic_load_draw_id: {
219                b.cursor = nir_after_instr(&intrin->instr);
220 
221                /* gl_VertexID and friends are stored by the VF as the last
222                 * vertex element.  We convert them to load_input intrinsics at
223                 * the right location.
224                 */
225                nir_intrinsic_instr *load =
226                   nir_intrinsic_instr_create(nir, nir_intrinsic_load_input);
227                load->src[0] = nir_src_for_ssa(nir_imm_int(&b, 0));
228 
229                nir_intrinsic_set_base(load, num_inputs);
230                switch (intrin->intrinsic) {
231                case nir_intrinsic_load_first_vertex:
232                   nir_intrinsic_set_component(load, 0);
233                   break;
234                case nir_intrinsic_load_base_instance:
235                   nir_intrinsic_set_component(load, 1);
236                   break;
237                case nir_intrinsic_load_vertex_id_zero_base:
238                   nir_intrinsic_set_component(load, 2);
239                   break;
240                case nir_intrinsic_load_instance_id:
241                   nir_intrinsic_set_component(load, 3);
242                   break;
243                case nir_intrinsic_load_draw_id:
244                case nir_intrinsic_load_is_indexed_draw:
245                   /* gl_DrawID and IsIndexedDraw are stored right after
246                    * gl_VertexID and friends if any of them exist.
247                    */
248                   nir_intrinsic_set_base(load, num_inputs + has_sgvs);
249                   if (intrin->intrinsic == nir_intrinsic_load_draw_id)
250                      nir_intrinsic_set_component(load, 0);
251                   else
252                      nir_intrinsic_set_component(load, 1);
253                   break;
254                default:
255                   unreachable("Invalid system value intrinsic");
256                }
257 
258                load->num_components = 1;
259                nir_ssa_dest_init(&load->instr, &load->dest, 1, 32, NULL);
260                nir_builder_instr_insert(&b, &load->instr);
261 
262                nir_ssa_def_rewrite_uses(&intrin->dest.ssa,
263                                         &load->dest.ssa);
264                nir_instr_remove(&intrin->instr);
265                break;
266             }
267 
268             case nir_intrinsic_load_input: {
269                /* Attributes come in a contiguous block, ordered by their
270                 * gl_vert_attrib value.  That means we can compute the slot
271                 * number for an attribute by masking out the enabled attributes
272                 * before it and counting the bits.
273                 */
274                int attr = nir_intrinsic_base(intrin);
275                uint64_t inputs_read = nir->info.inputs_read;
276                int slot = -1;
277                if (edgeflag_is_last) {
278                   inputs_read &= ~BITFIELD64_BIT(VERT_ATTRIB_EDGEFLAG);
279                   if (attr == VERT_ATTRIB_EDGEFLAG)
280                      slot = num_inputs - 1;
281                }
282                if (slot == -1)
283                   slot = util_bitcount64(inputs_read &
284                                          BITFIELD64_MASK(attr));
285                nir_intrinsic_set_base(intrin, slot);
286                break;
287             }
288 
289             default:
290                break; /* Nothing to do */
291             }
292          }
293       }
294    }
295 }
296 
297 void
brw_nir_lower_vue_inputs(nir_shader * nir,const struct brw_vue_map * vue_map)298 brw_nir_lower_vue_inputs(nir_shader *nir,
299                          const struct brw_vue_map *vue_map)
300 {
301    nir_foreach_shader_in_variable(var, nir)
302       var->data.driver_location = var->data.location;
303 
304    /* Inputs are stored in vec4 slots, so use type_size_vec4(). */
305    nir_lower_io(nir, nir_var_shader_in, type_size_vec4,
306                 nir_lower_io_lower_64bit_to_32);
307 
308    /* This pass needs actual constants */
309    nir_opt_constant_folding(nir);
310 
311    nir_io_add_const_offset_to_base(nir, nir_var_shader_in);
312 
313    nir_foreach_function(function, nir) {
314       if (!function->impl)
315          continue;
316 
317       nir_foreach_block(block, function->impl) {
318          nir_foreach_instr(instr, block) {
319             if (instr->type != nir_instr_type_intrinsic)
320                continue;
321 
322             nir_intrinsic_instr *intrin = nir_instr_as_intrinsic(instr);
323 
324             if (intrin->intrinsic == nir_intrinsic_load_input ||
325                 intrin->intrinsic == nir_intrinsic_load_per_vertex_input) {
326                /* Offset 0 is the VUE header, which contains
327                 * VARYING_SLOT_LAYER [.y], VARYING_SLOT_VIEWPORT [.z], and
328                 * VARYING_SLOT_PSIZ [.w].
329                 */
330                int varying = nir_intrinsic_base(intrin);
331                int vue_slot;
332                switch (varying) {
333                case VARYING_SLOT_PSIZ:
334                   nir_intrinsic_set_base(intrin, 0);
335                   nir_intrinsic_set_component(intrin, 3);
336                   break;
337 
338                default:
339                   vue_slot = vue_map->varying_to_slot[varying];
340                   assert(vue_slot != -1);
341                   nir_intrinsic_set_base(intrin, vue_slot);
342                   break;
343                }
344             }
345          }
346       }
347    }
348 }
349 
350 void
brw_nir_lower_tes_inputs(nir_shader * nir,const struct brw_vue_map * vue_map)351 brw_nir_lower_tes_inputs(nir_shader *nir, const struct brw_vue_map *vue_map)
352 {
353    nir_foreach_shader_in_variable(var, nir)
354       var->data.driver_location = var->data.location;
355 
356    nir_lower_io(nir, nir_var_shader_in, type_size_vec4,
357                 nir_lower_io_lower_64bit_to_32);
358 
359    /* This pass needs actual constants */
360    nir_opt_constant_folding(nir);
361 
362    nir_io_add_const_offset_to_base(nir, nir_var_shader_in);
363 
364    nir_foreach_function(function, nir) {
365       if (function->impl) {
366          nir_builder b;
367          nir_builder_init(&b, function->impl);
368          nir_foreach_block(block, function->impl) {
369             remap_patch_urb_offsets(block, &b, vue_map,
370                                     nir->info.tess._primitive_mode);
371          }
372       }
373    }
374 }
375 
376 /**
377  * Convert interpolateAtOffset() offsets from [-0.5, +0.5] floating point
378  * offsets to integer [-8, +7] offsets (in units of 1/16th of a pixel).
379  *
380  * We clamp to +7/16 on the upper end of the range, since +0.5 isn't
381  * representable in a S0.4 value; a naive conversion would give us -8/16,
382  * which is the opposite of what was intended.
383  *
384  * This is allowed by GL_ARB_gpu_shader5's quantization rules:
385  *
386  *    "Not all values of <offset> may be supported; x and y offsets may
387  *     be rounded to fixed-point values with the number of fraction bits
388  *     given by the implementation-dependent constant
389  *     FRAGMENT_INTERPOLATION_OFFSET_BITS."
390  */
391 static bool
lower_barycentric_at_offset(nir_builder * b,nir_instr * instr,void * data)392 lower_barycentric_at_offset(nir_builder *b, nir_instr *instr, void *data)
393 {
394    if (instr->type != nir_instr_type_intrinsic)
395       return false;
396 
397    nir_intrinsic_instr *intrin = nir_instr_as_intrinsic(instr);
398 
399    if (intrin->intrinsic != nir_intrinsic_load_barycentric_at_offset)
400       return false;
401 
402    b->cursor = nir_before_instr(instr);
403 
404    assert(intrin->src[0].ssa);
405    nir_ssa_def *offset =
406       nir_imin(b, nir_imm_int(b, 7),
407                nir_f2i32(b, nir_fmul(b, nir_imm_float(b, 16),
408                                      intrin->src[0].ssa)));
409 
410    nir_instr_rewrite_src(instr, &intrin->src[0], nir_src_for_ssa(offset));
411 
412    return true;
413 }
414 
415 void
brw_nir_lower_fs_inputs(nir_shader * nir,const struct intel_device_info * devinfo,const struct brw_wm_prog_key * key)416 brw_nir_lower_fs_inputs(nir_shader *nir,
417                         const struct intel_device_info *devinfo,
418                         const struct brw_wm_prog_key *key)
419 {
420    nir_foreach_shader_in_variable(var, nir) {
421       var->data.driver_location = var->data.location;
422 
423       /* Apply default interpolation mode.
424        *
425        * Everything defaults to smooth except for the legacy GL color
426        * built-in variables, which might be flat depending on API state.
427        */
428       if (var->data.interpolation == INTERP_MODE_NONE) {
429          const bool flat = key->flat_shade &&
430             (var->data.location == VARYING_SLOT_COL0 ||
431              var->data.location == VARYING_SLOT_COL1);
432 
433          var->data.interpolation = flat ? INTERP_MODE_FLAT
434                                         : INTERP_MODE_SMOOTH;
435       }
436 
437       /* On Ironlake and below, there is only one interpolation mode.
438        * Centroid interpolation doesn't mean anything on this hardware --
439        * there is no multisampling.
440        */
441       if (devinfo->ver < 6) {
442          var->data.centroid = false;
443          var->data.sample = false;
444       }
445    }
446 
447    nir_lower_io_options lower_io_options = nir_lower_io_lower_64bit_to_32;
448    if (key->persample_interp)
449       lower_io_options |= nir_lower_io_force_sample_interpolation;
450 
451    nir_lower_io(nir, nir_var_shader_in, type_size_vec4, lower_io_options);
452    if (devinfo->ver >= 11)
453       nir_lower_interpolation(nir, ~0);
454 
455    if (!key->multisample_fbo)
456       nir_lower_single_sampled(nir);
457 
458    nir_shader_instructions_pass(nir, lower_barycentric_at_offset,
459                                 nir_metadata_block_index |
460                                 nir_metadata_dominance,
461                                 NULL);
462 
463    /* This pass needs actual constants */
464    nir_opt_constant_folding(nir);
465 
466    nir_io_add_const_offset_to_base(nir, nir_var_shader_in);
467 }
468 
469 void
brw_nir_lower_vue_outputs(nir_shader * nir)470 brw_nir_lower_vue_outputs(nir_shader *nir)
471 {
472    nir_foreach_shader_out_variable(var, nir) {
473       var->data.driver_location = var->data.location;
474    }
475 
476    nir_lower_io(nir, nir_var_shader_out, type_size_vec4,
477                 nir_lower_io_lower_64bit_to_32);
478 }
479 
480 void
brw_nir_lower_tcs_outputs(nir_shader * nir,const struct brw_vue_map * vue_map,enum tess_primitive_mode tes_primitive_mode)481 brw_nir_lower_tcs_outputs(nir_shader *nir, const struct brw_vue_map *vue_map,
482                           enum tess_primitive_mode tes_primitive_mode)
483 {
484    nir_foreach_shader_out_variable(var, nir) {
485       var->data.driver_location = var->data.location;
486    }
487 
488    nir_lower_io(nir, nir_var_shader_out, type_size_vec4,
489                 nir_lower_io_lower_64bit_to_32);
490 
491    /* This pass needs actual constants */
492    nir_opt_constant_folding(nir);
493 
494    nir_io_add_const_offset_to_base(nir, nir_var_shader_out);
495 
496    nir_foreach_function(function, nir) {
497       if (function->impl) {
498          nir_builder b;
499          nir_builder_init(&b, function->impl);
500          nir_foreach_block(block, function->impl) {
501             remap_patch_urb_offsets(block, &b, vue_map, tes_primitive_mode);
502          }
503       }
504    }
505 }
506 
507 void
brw_nir_lower_fs_outputs(nir_shader * nir)508 brw_nir_lower_fs_outputs(nir_shader *nir)
509 {
510    nir_foreach_shader_out_variable(var, nir) {
511       var->data.driver_location =
512          SET_FIELD(var->data.index, BRW_NIR_FRAG_OUTPUT_INDEX) |
513          SET_FIELD(var->data.location, BRW_NIR_FRAG_OUTPUT_LOCATION);
514    }
515 
516    nir_lower_io(nir, nir_var_shader_out, type_size_dvec4, 0);
517 }
518 
519 #define OPT(pass, ...) ({                                  \
520    bool this_progress = false;                             \
521    NIR_PASS(this_progress, nir, pass, ##__VA_ARGS__);      \
522    if (this_progress)                                      \
523       progress = true;                                     \
524    this_progress;                                          \
525 })
526 
527 void
brw_nir_optimize(nir_shader * nir,const struct brw_compiler * compiler,bool is_scalar,bool allow_copies)528 brw_nir_optimize(nir_shader *nir, const struct brw_compiler *compiler,
529                  bool is_scalar, bool allow_copies)
530 {
531    bool progress;
532    unsigned lower_flrp =
533       (nir->options->lower_flrp16 ? 16 : 0) |
534       (nir->options->lower_flrp32 ? 32 : 0) |
535       (nir->options->lower_flrp64 ? 64 : 0);
536 
537    do {
538       progress = false;
539       OPT(nir_split_array_vars, nir_var_function_temp);
540       OPT(nir_shrink_vec_array_vars, nir_var_function_temp);
541       OPT(nir_opt_deref);
542       if (OPT(nir_opt_memcpy))
543          OPT(nir_split_var_copies);
544       OPT(nir_lower_vars_to_ssa);
545       if (allow_copies) {
546          /* Only run this pass in the first call to brw_nir_optimize.  Later
547           * calls assume that we've lowered away any copy_deref instructions
548           * and we don't want to introduce any more.
549           */
550          OPT(nir_opt_find_array_copies);
551       }
552       OPT(nir_opt_copy_prop_vars);
553       OPT(nir_opt_dead_write_vars);
554       OPT(nir_opt_combine_stores, nir_var_all);
555 
556       OPT(nir_opt_ray_queries);
557 
558       if (is_scalar) {
559          OPT(nir_lower_alu_to_scalar, NULL, NULL);
560       } else {
561          OPT(nir_opt_shrink_stores, true);
562          OPT(nir_opt_shrink_vectors);
563       }
564 
565       OPT(nir_copy_prop);
566 
567       if (is_scalar) {
568          OPT(nir_lower_phis_to_scalar, false);
569       }
570 
571       OPT(nir_copy_prop);
572       OPT(nir_opt_dce);
573       OPT(nir_opt_cse);
574       OPT(nir_opt_combine_stores, nir_var_all);
575 
576       /* Passing 0 to the peephole select pass causes it to convert
577        * if-statements that contain only move instructions in the branches
578        * regardless of the count.
579        *
580        * Passing 1 to the peephole select pass causes it to convert
581        * if-statements that contain at most a single ALU instruction (total)
582        * in both branches.  Before Gfx6, some math instructions were
583        * prohibitively expensive and the results of compare operations need an
584        * extra resolve step.  For these reasons, this pass is more harmful
585        * than good on those platforms.
586        *
587        * For indirect loads of uniforms (push constants), we assume that array
588        * indices will nearly always be in bounds and the cost of the load is
589        * low.  Therefore there shouldn't be a performance benefit to avoid it.
590        * However, in vec4 tessellation shaders, these loads operate by
591        * actually pulling from memory.
592        */
593       const bool is_vec4_tessellation = !is_scalar &&
594          (nir->info.stage == MESA_SHADER_TESS_CTRL ||
595           nir->info.stage == MESA_SHADER_TESS_EVAL);
596       OPT(nir_opt_peephole_select, 0, !is_vec4_tessellation, false);
597       OPT(nir_opt_peephole_select, 8, !is_vec4_tessellation,
598           compiler->devinfo->ver >= 6);
599 
600       OPT(nir_opt_intrinsics);
601       OPT(nir_opt_idiv_const, 32);
602       OPT(nir_opt_algebraic);
603       OPT(nir_lower_constant_convert_alu_types);
604       OPT(nir_opt_constant_folding);
605 
606       if (lower_flrp != 0) {
607          if (OPT(nir_lower_flrp,
608                  lower_flrp,
609                  false /* always_precise */)) {
610             OPT(nir_opt_constant_folding);
611          }
612 
613          /* Nothing should rematerialize any flrps, so we only need to do this
614           * lowering once.
615           */
616          lower_flrp = 0;
617       }
618 
619       OPT(nir_opt_dead_cf);
620       if (OPT(nir_opt_trivial_continues)) {
621          /* If nir_opt_trivial_continues makes progress, then we need to clean
622           * things up if we want any hope of nir_opt_if or nir_opt_loop_unroll
623           * to make progress.
624           */
625          OPT(nir_copy_prop);
626          OPT(nir_opt_dce);
627       }
628       OPT(nir_opt_if, nir_opt_if_optimize_phi_true_false);
629       OPT(nir_opt_conditional_discard);
630       if (nir->options->max_unroll_iterations != 0) {
631          OPT(nir_opt_loop_unroll);
632       }
633       OPT(nir_opt_remove_phis);
634       OPT(nir_opt_gcm, false);
635       OPT(nir_opt_undef);
636       OPT(nir_lower_pack);
637    } while (progress);
638 
639    /* Workaround Gfxbench unused local sampler variable which will trigger an
640     * assert in the opt_large_constants pass.
641     */
642    OPT(nir_remove_dead_variables, nir_var_function_temp, NULL);
643 }
644 
645 static unsigned
lower_bit_size_callback(const nir_instr * instr,UNUSED void * data)646 lower_bit_size_callback(const nir_instr *instr, UNUSED void *data)
647 {
648    const struct brw_compiler *compiler = (const struct brw_compiler *) data;
649    const struct intel_device_info *devinfo = compiler->devinfo;
650 
651    switch (instr->type) {
652    case nir_instr_type_alu: {
653       nir_alu_instr *alu = nir_instr_as_alu(instr);
654       switch (alu->op) {
655       case nir_op_bit_count:
656       case nir_op_ufind_msb:
657       case nir_op_ifind_msb:
658       case nir_op_find_lsb:
659          /* These are handled specially because the destination is always
660           * 32-bit and so the bit size of the instruction is given by the
661           * source.
662           */
663          assert(alu->src[0].src.is_ssa);
664          return alu->src[0].src.ssa->bit_size == 32 ? 0 : 32;
665       default:
666          break;
667       }
668 
669       assert(alu->dest.dest.is_ssa);
670       if (alu->dest.dest.ssa.bit_size >= 32)
671          return 0;
672 
673       /* Note: nir_op_iabs and nir_op_ineg are not lowered here because the
674        * 8-bit ABS or NEG instruction should eventually get copy propagated
675        * into the MOV that does the type conversion.  This results in far
676        * fewer MOV instructions.
677        */
678       switch (alu->op) {
679       case nir_op_idiv:
680       case nir_op_imod:
681       case nir_op_irem:
682       case nir_op_udiv:
683       case nir_op_umod:
684       case nir_op_fceil:
685       case nir_op_ffloor:
686       case nir_op_ffract:
687       case nir_op_fround_even:
688       case nir_op_ftrunc:
689          return 32;
690       case nir_op_frcp:
691       case nir_op_frsq:
692       case nir_op_fsqrt:
693       case nir_op_fpow:
694       case nir_op_fexp2:
695       case nir_op_flog2:
696       case nir_op_fsin:
697       case nir_op_fcos:
698          return devinfo->ver < 9 ? 32 : 0;
699       case nir_op_isign:
700          assert(!"Should have been lowered by nir_opt_algebraic.");
701          return 0;
702       default:
703          if (nir_op_infos[alu->op].num_inputs >= 2 &&
704              alu->dest.dest.ssa.bit_size == 8)
705             return 16;
706 
707          if (nir_alu_instr_is_comparison(alu) &&
708              alu->src[0].src.ssa->bit_size == 8)
709             return 16;
710 
711          return 0;
712       }
713       break;
714    }
715 
716    case nir_instr_type_intrinsic: {
717       nir_intrinsic_instr *intrin = nir_instr_as_intrinsic(instr);
718       switch (intrin->intrinsic) {
719       case nir_intrinsic_read_invocation:
720       case nir_intrinsic_read_first_invocation:
721       case nir_intrinsic_vote_feq:
722       case nir_intrinsic_vote_ieq:
723       case nir_intrinsic_shuffle:
724       case nir_intrinsic_shuffle_xor:
725       case nir_intrinsic_shuffle_up:
726       case nir_intrinsic_shuffle_down:
727       case nir_intrinsic_quad_broadcast:
728       case nir_intrinsic_quad_swap_horizontal:
729       case nir_intrinsic_quad_swap_vertical:
730       case nir_intrinsic_quad_swap_diagonal:
731          if (intrin->src[0].ssa->bit_size == 8)
732             return 16;
733          return 0;
734 
735       case nir_intrinsic_reduce:
736       case nir_intrinsic_inclusive_scan:
737       case nir_intrinsic_exclusive_scan:
738          /* There are a couple of register region issues that make things
739           * complicated for 8-bit types:
740           *
741           *    1. Only raw moves are allowed to write to a packed 8-bit
742           *       destination.
743           *    2. If we use a strided destination, the efficient way to do
744           *       scan operations ends up using strides that are too big to
745           *       encode in an instruction.
746           *
747           * To get around these issues, we just do all 8-bit scan operations
748           * in 16 bits.  It's actually fewer instructions than what we'd have
749           * to do if we were trying to do it in native 8-bit types and the
750           * results are the same once we truncate to 8 bits at the end.
751           */
752          if (intrin->dest.ssa.bit_size == 8)
753             return 16;
754          return 0;
755 
756       default:
757          return 0;
758       }
759       break;
760    }
761 
762    case nir_instr_type_phi: {
763       nir_phi_instr *phi = nir_instr_as_phi(instr);
764       if (phi->dest.ssa.bit_size == 8)
765          return 16;
766       return 0;
767    }
768 
769    default:
770       return 0;
771    }
772 }
773 
774 /* On gfx12.5+, if the offsets are not both constant and in the {-8,7} range,
775  * we will have nir_lower_tex() lower the source offset by returning true from
776  * this filter function.
777  */
778 static bool
lower_xehp_tg4_offset_filter(const nir_instr * instr,UNUSED const void * data)779 lower_xehp_tg4_offset_filter(const nir_instr *instr, UNUSED const void *data)
780 {
781    if (instr->type != nir_instr_type_tex)
782       return false;
783 
784    nir_tex_instr *tex = nir_instr_as_tex(instr);
785 
786    if (tex->op != nir_texop_tg4)
787       return false;
788 
789    int offset_index = nir_tex_instr_src_index(tex, nir_tex_src_offset);
790    if (offset_index < 0)
791       return false;
792 
793    if (!nir_src_is_const(tex->src[offset_index].src))
794       return true;
795 
796    int64_t offset_x = nir_src_comp_as_int(tex->src[offset_index].src, 0);
797    int64_t offset_y = nir_src_comp_as_int(tex->src[offset_index].src, 1);
798 
799    return offset_x < -8 || offset_x > 7 || offset_y < -8 || offset_y > 7;
800 }
801 
802 /* Does some simple lowering and runs the standard suite of optimizations
803  *
804  * This is intended to be called more-or-less directly after you get the
805  * shader out of GLSL or some other source.  While it is geared towards i965,
806  * it is not at all generator-specific except for the is_scalar flag.  Even
807  * there, it is safe to call with is_scalar = false for a shader that is
808  * intended for the FS backend as long as nir_optimize is called again with
809  * is_scalar = true to scalarize everything prior to code gen.
810  */
811 void
brw_preprocess_nir(const struct brw_compiler * compiler,nir_shader * nir,const nir_shader * softfp64)812 brw_preprocess_nir(const struct brw_compiler *compiler, nir_shader *nir,
813                    const nir_shader *softfp64)
814 {
815    const struct intel_device_info *devinfo = compiler->devinfo;
816    UNUSED bool progress; /* Written by OPT */
817 
818    const bool is_scalar = compiler->scalar_stage[nir->info.stage];
819 
820    nir_validate_ssa_dominance(nir, "before brw_preprocess_nir");
821 
822    if (is_scalar) {
823       OPT(nir_lower_alu_to_scalar, NULL, NULL);
824    }
825 
826    if (nir->info.stage == MESA_SHADER_GEOMETRY)
827       OPT(nir_lower_gs_intrinsics, 0);
828 
829    /* See also brw_nir_trig_workarounds.py */
830    if (compiler->precise_trig &&
831        !(devinfo->ver >= 10 || devinfo->platform == INTEL_PLATFORM_KBL))
832       OPT(brw_nir_apply_trig_workarounds);
833 
834    if (devinfo->ver >= 12)
835       OPT(brw_nir_clamp_image_1d_2d_array_sizes);
836 
837    const nir_lower_tex_options tex_options = {
838       .lower_txp = ~0,
839       .lower_txf_offset = true,
840       .lower_rect_offset = true,
841       .lower_txd_cube_map = true,
842       .lower_txd_3d = devinfo->verx10 >= 125,    /* Wa_1209978020 */
843       .lower_txd_array = devinfo->verx10 >= 125, /* Wa_1209978020 */
844       .lower_txb_shadow_clamp = true,
845       .lower_txd_shadow_clamp = true,
846       .lower_txd_offset_clamp = true,
847       .lower_tg4_offsets = true,
848       .lower_txs_lod = true, /* Wa_14012320009 */
849       .lower_offset_filter =
850          devinfo->verx10 >= 125 ? lower_xehp_tg4_offset_filter : NULL,
851       .lower_invalid_implicit_lod = true,
852    };
853 
854    OPT(nir_lower_tex, &tex_options);
855    OPT(nir_normalize_cubemap_coords);
856 
857    OPT(nir_lower_global_vars_to_local);
858 
859    OPT(nir_split_var_copies);
860    OPT(nir_split_struct_vars, nir_var_function_temp);
861 
862    brw_nir_optimize(nir, compiler, is_scalar, true);
863 
864    OPT(nir_lower_doubles, softfp64, nir->options->lower_doubles_options);
865    OPT(nir_lower_int64);
866 
867    OPT(nir_lower_bit_size, lower_bit_size_callback, (void *)compiler);
868 
869    if (is_scalar) {
870       OPT(nir_lower_load_const_to_scalar);
871    }
872 
873    /* Lower a bunch of stuff */
874    OPT(nir_lower_var_copies);
875 
876    /* This needs to be run after the first optimization pass but before we
877     * lower indirect derefs away
878     */
879    if (compiler->supports_shader_constants) {
880       OPT(nir_opt_large_constants, NULL, 32);
881    }
882 
883    OPT(nir_lower_system_values);
884    OPT(nir_lower_compute_system_values, NULL);
885 
886    const nir_lower_subgroups_options subgroups_options = {
887       .ballot_bit_size = 32,
888       .ballot_components = 1,
889       .lower_to_scalar = true,
890       .lower_vote_trivial = !is_scalar,
891       .lower_relative_shuffle = true,
892       .lower_quad_broadcast_dynamic = true,
893       .lower_elect = true,
894    };
895    OPT(nir_lower_subgroups, &subgroups_options);
896 
897    nir_variable_mode indirect_mask =
898       brw_nir_no_indirect_mask(compiler, nir->info.stage);
899    OPT(nir_lower_indirect_derefs, indirect_mask, UINT32_MAX);
900 
901    /* Even in cases where we can handle indirect temporaries via scratch, we
902     * it can still be expensive.  Lower indirects on small arrays to
903     * conditional load/stores.
904     *
905     * The threshold of 16 was chosen semi-arbitrarily.  The idea is that an
906     * indirect on an array of 16 elements is about 30 instructions at which
907     * point, you may be better off doing a send.  With a SIMD8 program, 16
908     * floats is 1/8 of the entire register file.  Any array larger than that
909     * is likely to cause pressure issues.  Also, this value is sufficiently
910     * high that the benchmarks known to suffer from large temporary array
911     * issues are helped but nothing else in shader-db is hurt except for maybe
912     * that one kerbal space program shader.
913     */
914    if (is_scalar && !(indirect_mask & nir_var_function_temp))
915       OPT(nir_lower_indirect_derefs, nir_var_function_temp, 16);
916 
917    /* Lower array derefs of vectors for SSBO and UBO loads.  For both UBOs and
918     * SSBOs, our back-end is capable of loading an entire vec4 at a time and
919     * we would like to take advantage of that whenever possible regardless of
920     * whether or not the app gives us full loads.  This should allow the
921     * optimizer to combine UBO and SSBO load operations and save us some send
922     * messages.
923     */
924    OPT(nir_lower_array_deref_of_vec,
925        nir_var_mem_ubo | nir_var_mem_ssbo,
926        nir_lower_direct_array_deref_of_vec_load);
927 
928    /* Get rid of split copies */
929    brw_nir_optimize(nir, compiler, is_scalar, false);
930 }
931 
932 void
brw_nir_link_shaders(const struct brw_compiler * compiler,nir_shader * producer,nir_shader * consumer)933 brw_nir_link_shaders(const struct brw_compiler *compiler,
934                      nir_shader *producer, nir_shader *consumer)
935 {
936    if (producer->info.stage == MESA_SHADER_MESH &&
937        consumer->info.stage == MESA_SHADER_FRAGMENT) {
938       /* gl_MeshPerPrimitiveNV[].gl_ViewportIndex, gl_PrimitiveID and gl_Layer
939        * are per primitive, but fragment shader does not have them marked as
940        * such. Add the annotation here.
941        */
942       nir_foreach_shader_in_variable(var, consumer) {
943          switch (var->data.location) {
944             case VARYING_SLOT_LAYER:
945             case VARYING_SLOT_PRIMITIVE_ID:
946             case VARYING_SLOT_VIEWPORT:
947                var->data.per_primitive = 1;
948                break;
949             default:
950                continue;
951          }
952       }
953    }
954 
955    nir_lower_io_arrays_to_elements(producer, consumer);
956    nir_validate_shader(producer, "after nir_lower_io_arrays_to_elements");
957    nir_validate_shader(consumer, "after nir_lower_io_arrays_to_elements");
958 
959    const bool p_is_scalar = compiler->scalar_stage[producer->info.stage];
960    const bool c_is_scalar = compiler->scalar_stage[consumer->info.stage];
961 
962    if (p_is_scalar && c_is_scalar) {
963       NIR_PASS(_, producer, nir_lower_io_to_scalar_early, nir_var_shader_out);
964       NIR_PASS(_, consumer, nir_lower_io_to_scalar_early, nir_var_shader_in);
965       brw_nir_optimize(producer, compiler, p_is_scalar, false);
966       brw_nir_optimize(consumer, compiler, c_is_scalar, false);
967    }
968 
969    if (nir_link_opt_varyings(producer, consumer))
970       brw_nir_optimize(consumer, compiler, c_is_scalar, false);
971 
972    NIR_PASS(_, producer, nir_remove_dead_variables, nir_var_shader_out, NULL);
973    NIR_PASS(_, consumer, nir_remove_dead_variables, nir_var_shader_in, NULL);
974 
975    if (nir_remove_unused_varyings(producer, consumer)) {
976       if (should_print_nir(producer)) {
977          printf("nir_remove_unused_varyings\n");
978          nir_print_shader(producer, stdout);
979       }
980       if (should_print_nir(consumer)) {
981          printf("nir_remove_unused_varyings\n");
982          nir_print_shader(consumer, stdout);
983       }
984 
985       NIR_PASS(_, producer, nir_lower_global_vars_to_local);
986       NIR_PASS(_, consumer, nir_lower_global_vars_to_local);
987 
988       /* The backend might not be able to handle indirects on
989        * temporaries so we need to lower indirects on any of the
990        * varyings we have demoted here.
991        */
992       NIR_PASS(_, producer, nir_lower_indirect_derefs,
993                   brw_nir_no_indirect_mask(compiler, producer->info.stage),
994                   UINT32_MAX);
995       NIR_PASS(_, consumer, nir_lower_indirect_derefs,
996                   brw_nir_no_indirect_mask(compiler, consumer->info.stage),
997                   UINT32_MAX);
998 
999       brw_nir_optimize(producer, compiler, p_is_scalar, false);
1000       brw_nir_optimize(consumer, compiler, c_is_scalar, false);
1001    }
1002 
1003    NIR_PASS(_, producer, nir_lower_io_to_vector, nir_var_shader_out);
1004    NIR_PASS(_, producer, nir_opt_combine_stores, nir_var_shader_out);
1005    NIR_PASS(_, consumer, nir_lower_io_to_vector, nir_var_shader_in);
1006 
1007    if (producer->info.stage != MESA_SHADER_TESS_CTRL &&
1008        producer->info.stage != MESA_SHADER_MESH &&
1009        producer->info.stage != MESA_SHADER_TASK) {
1010       /* Calling lower_io_to_vector creates output variable writes with
1011        * write-masks.  On non-TCS outputs, the back-end can't handle it and we
1012        * need to call nir_lower_io_to_temporaries to get rid of them.  This,
1013        * in turn, creates temporary variables and extra copy_deref intrinsics
1014        * that we need to clean up.
1015        *
1016        * Note Mesh/Task don't support I/O as temporaries (I/O is shared
1017        * between whole workgroup, possibly using multiple HW threads). For
1018        * those write-mask in output is handled by I/O lowering.
1019        */
1020       NIR_PASS_V(producer, nir_lower_io_to_temporaries,
1021                  nir_shader_get_entrypoint(producer), true, false);
1022       NIR_PASS(_, producer, nir_lower_global_vars_to_local);
1023       NIR_PASS(_, producer, nir_split_var_copies);
1024       NIR_PASS(_, producer, nir_lower_var_copies);
1025    }
1026 }
1027 
1028 static bool
brw_nir_should_vectorize_mem(unsigned align_mul,unsigned align_offset,unsigned bit_size,unsigned num_components,nir_intrinsic_instr * low,nir_intrinsic_instr * high,void * data)1029 brw_nir_should_vectorize_mem(unsigned align_mul, unsigned align_offset,
1030                              unsigned bit_size,
1031                              unsigned num_components,
1032                              nir_intrinsic_instr *low,
1033                              nir_intrinsic_instr *high,
1034                              void *data)
1035 {
1036    /* Don't combine things to generate 64-bit loads/stores.  We have to split
1037     * those back into 32-bit ones anyway and UBO loads aren't split in NIR so
1038     * we don't want to make a mess for the back-end.
1039     */
1040    if (bit_size > 32)
1041       return false;
1042 
1043    /* We can handle at most a vec4 right now.  Anything bigger would get
1044     * immediately split by brw_nir_lower_mem_access_bit_sizes anyway.
1045     */
1046    if (num_components > 4)
1047       return false;
1048 
1049 
1050    uint32_t align;
1051    if (align_offset)
1052       align = 1 << (ffs(align_offset) - 1);
1053    else
1054       align = align_mul;
1055 
1056    if (align < bit_size / 8)
1057       return false;
1058 
1059    return true;
1060 }
1061 
1062 static
combine_all_barriers(nir_intrinsic_instr * a,nir_intrinsic_instr * b,void * data)1063 bool combine_all_barriers(nir_intrinsic_instr *a,
1064                           nir_intrinsic_instr *b,
1065                           void *data)
1066 {
1067    /* Translation to backend IR will get rid of modes we don't care about, so
1068     * no harm in always combining them.
1069     *
1070     * TODO: While HW has only ACQUIRE|RELEASE fences, we could improve the
1071     * scheduling so that it can take advantage of the different semantics.
1072     */
1073    nir_intrinsic_set_memory_modes(a, nir_intrinsic_memory_modes(a) |
1074                                      nir_intrinsic_memory_modes(b));
1075    nir_intrinsic_set_memory_semantics(a, nir_intrinsic_memory_semantics(a) |
1076                                          nir_intrinsic_memory_semantics(b));
1077    nir_intrinsic_set_memory_scope(a, MAX2(nir_intrinsic_memory_scope(a),
1078                                           nir_intrinsic_memory_scope(b)));
1079    return true;
1080 }
1081 
1082 static void
brw_vectorize_lower_mem_access(nir_shader * nir,const struct brw_compiler * compiler,bool is_scalar,bool robust_buffer_access)1083 brw_vectorize_lower_mem_access(nir_shader *nir,
1084                                const struct brw_compiler *compiler,
1085                                bool is_scalar,
1086                                bool robust_buffer_access)
1087 {
1088    const struct intel_device_info *devinfo = compiler->devinfo;
1089    bool progress = false;
1090 
1091    if (is_scalar) {
1092       nir_load_store_vectorize_options options = {
1093          .modes = nir_var_mem_ubo | nir_var_mem_ssbo |
1094                   nir_var_mem_global | nir_var_mem_shared |
1095                   nir_var_mem_task_payload,
1096          .callback = brw_nir_should_vectorize_mem,
1097          .robust_modes = (nir_variable_mode)0,
1098       };
1099 
1100       if (robust_buffer_access) {
1101          options.robust_modes = nir_var_mem_ubo | nir_var_mem_ssbo |
1102                                 nir_var_mem_global;
1103       }
1104 
1105       OPT(nir_opt_load_store_vectorize, &options);
1106    }
1107 
1108    OPT(brw_nir_lower_mem_access_bit_sizes, devinfo);
1109 
1110    while (progress) {
1111       progress = false;
1112 
1113       OPT(nir_lower_pack);
1114       OPT(nir_copy_prop);
1115       OPT(nir_opt_dce);
1116       OPT(nir_opt_cse);
1117       OPT(nir_opt_algebraic);
1118       OPT(nir_opt_constant_folding);
1119    }
1120 }
1121 
1122 static bool
nir_shader_has_local_variables(const nir_shader * nir)1123 nir_shader_has_local_variables(const nir_shader *nir)
1124 {
1125    nir_foreach_function(func, nir) {
1126       if (func->impl && !exec_list_is_empty(&func->impl->locals))
1127          return true;
1128    }
1129 
1130    return false;
1131 }
1132 
1133 /* Prepare the given shader for codegen
1134  *
1135  * This function is intended to be called right before going into the actual
1136  * backend and is highly backend-specific.  Also, once this function has been
1137  * called on a shader, it will no longer be in SSA form so most optimizations
1138  * will not work.
1139  */
1140 void
brw_postprocess_nir(nir_shader * nir,const struct brw_compiler * compiler,bool is_scalar,bool debug_enabled,bool robust_buffer_access)1141 brw_postprocess_nir(nir_shader *nir, const struct brw_compiler *compiler,
1142                     bool is_scalar, bool debug_enabled,
1143                     bool robust_buffer_access)
1144 {
1145    const struct intel_device_info *devinfo = compiler->devinfo;
1146 
1147    UNUSED bool progress; /* Written by OPT */
1148 
1149    OPT(nir_lower_bit_size, lower_bit_size_callback, (void *)compiler);
1150 
1151    OPT(brw_nir_lower_scoped_barriers);
1152    OPT(nir_opt_combine_memory_barriers, combine_all_barriers, NULL);
1153 
1154    do {
1155       progress = false;
1156       OPT(nir_opt_algebraic_before_ffma);
1157    } while (progress);
1158 
1159    if (devinfo->verx10 >= 125) {
1160       const nir_lower_idiv_options options = {
1161          .imprecise_32bit_lowering = false,
1162          .allow_fp16 = false
1163       };
1164       OPT(nir_lower_idiv, &options);
1165    }
1166 
1167    if (gl_shader_stage_can_set_fragment_shading_rate(nir->info.stage))
1168       brw_nir_lower_shading_rate_output(nir);
1169 
1170    brw_nir_optimize(nir, compiler, is_scalar, false);
1171 
1172    if (is_scalar && nir_shader_has_local_variables(nir)) {
1173       OPT(nir_lower_vars_to_explicit_types, nir_var_function_temp,
1174           glsl_get_natural_size_align_bytes);
1175       OPT(nir_lower_explicit_io, nir_var_function_temp,
1176           nir_address_format_32bit_offset);
1177       brw_nir_optimize(nir, compiler, is_scalar, false);
1178    }
1179 
1180    brw_vectorize_lower_mem_access(nir, compiler, is_scalar,
1181                                   robust_buffer_access);
1182 
1183    if (OPT(nir_lower_int64))
1184       brw_nir_optimize(nir, compiler, is_scalar, false);
1185 
1186    if (devinfo->ver >= 6) {
1187       /* Try and fuse multiply-adds */
1188       OPT(brw_nir_opt_peephole_ffma);
1189    }
1190 
1191    if (OPT(nir_opt_comparison_pre)) {
1192       OPT(nir_copy_prop);
1193       OPT(nir_opt_dce);
1194       OPT(nir_opt_cse);
1195 
1196       /* Do the select peepehole again.  nir_opt_comparison_pre (combined with
1197        * the other optimization passes) will have removed at least one
1198        * instruction from one of the branches of the if-statement, so now it
1199        * might be under the threshold of conversion to bcsel.
1200        *
1201        * See brw_nir_optimize for the explanation of is_vec4_tessellation.
1202        */
1203       const bool is_vec4_tessellation = !is_scalar &&
1204          (nir->info.stage == MESA_SHADER_TESS_CTRL ||
1205           nir->info.stage == MESA_SHADER_TESS_EVAL);
1206       OPT(nir_opt_peephole_select, 0, is_vec4_tessellation, false);
1207       OPT(nir_opt_peephole_select, 1, is_vec4_tessellation,
1208           compiler->devinfo->ver >= 6);
1209    }
1210 
1211    do {
1212       progress = false;
1213       if (OPT(nir_opt_algebraic_late)) {
1214          /* At this late stage, anything that makes more constants will wreak
1215           * havok on the vec4 backend.  The handling of constants in the vec4
1216           * backend is not good.
1217           */
1218          if (is_scalar)
1219             OPT(nir_opt_constant_folding);
1220 
1221          OPT(nir_copy_prop);
1222          OPT(nir_opt_dce);
1223          OPT(nir_opt_cse);
1224       }
1225    } while (progress);
1226 
1227 
1228    OPT(brw_nir_lower_conversions);
1229 
1230    if (is_scalar)
1231       OPT(nir_lower_alu_to_scalar, NULL, NULL);
1232 
1233    while (OPT(nir_opt_algebraic_distribute_src_mods)) {
1234       OPT(nir_copy_prop);
1235       OPT(nir_opt_dce);
1236       OPT(nir_opt_cse);
1237    }
1238 
1239    OPT(nir_copy_prop);
1240    OPT(nir_opt_dce);
1241    OPT(nir_opt_move, nir_move_comparisons);
1242    OPT(nir_opt_dead_cf);
1243 
1244    NIR_PASS_V(nir, nir_convert_to_lcssa, true, true);
1245    NIR_PASS_V(nir, nir_divergence_analysis);
1246 
1247    /* TODO: Enable nir_opt_uniform_atomics on Gfx7.x too.
1248     * It currently fails Vulkan tests on Haswell for an unknown reason.
1249     *
1250     * TODO: Using this optimization on RT/OpenCL kernels also seems to cause
1251     *       issues. Until we can understand those issues, disable it.
1252     */
1253    bool opt_uniform_atomic_stage_allowed =
1254       devinfo->ver >= 8 &&
1255       nir->info.stage != MESA_SHADER_KERNEL &&
1256       nir->info.stage != MESA_SHADER_RAYGEN &&
1257       !gl_shader_stage_is_callable(nir->info.stage);
1258 
1259    if (opt_uniform_atomic_stage_allowed && OPT(nir_opt_uniform_atomics)) {
1260       const nir_lower_subgroups_options subgroups_options = {
1261          .ballot_bit_size = 32,
1262          .ballot_components = 1,
1263          .lower_elect = true,
1264       };
1265       OPT(nir_lower_subgroups, &subgroups_options);
1266 
1267       if (OPT(nir_lower_int64))
1268          brw_nir_optimize(nir, compiler, is_scalar, false);
1269    }
1270 
1271    /* Clean up LCSSA phis */
1272    OPT(nir_opt_remove_phis);
1273 
1274    OPT(nir_lower_bool_to_int32);
1275    OPT(nir_copy_prop);
1276    OPT(nir_opt_dce);
1277 
1278    OPT(nir_lower_locals_to_regs);
1279 
1280    if (unlikely(debug_enabled)) {
1281       /* Re-index SSA defs so we print more sensible numbers. */
1282       nir_foreach_function(function, nir) {
1283          if (function->impl)
1284             nir_index_ssa_defs(function->impl);
1285       }
1286 
1287       fprintf(stderr, "NIR (SSA form) for %s shader:\n",
1288               _mesa_shader_stage_to_string(nir->info.stage));
1289       nir_print_shader(nir, stderr);
1290    }
1291 
1292    nir_validate_ssa_dominance(nir, "before nir_convert_from_ssa");
1293 
1294    OPT(nir_convert_from_ssa, true);
1295 
1296    if (!is_scalar) {
1297       OPT(nir_move_vec_src_uses_to_dest);
1298       OPT(nir_lower_vec_to_movs, NULL, NULL);
1299    }
1300 
1301    OPT(nir_opt_dce);
1302 
1303    if (OPT(nir_opt_rematerialize_compares))
1304       OPT(nir_opt_dce);
1305 
1306    /* This is the last pass we run before we start emitting stuff.  It
1307     * determines when we need to insert boolean resolves on Gen <= 5.  We
1308     * run it last because it stashes data in instr->pass_flags and we don't
1309     * want that to be squashed by other NIR passes.
1310     */
1311    if (devinfo->ver <= 5)
1312       brw_nir_analyze_boolean_resolves(nir);
1313 
1314    nir_sweep(nir);
1315 
1316    if (unlikely(debug_enabled)) {
1317       fprintf(stderr, "NIR (final form) for %s shader:\n",
1318               _mesa_shader_stage_to_string(nir->info.stage));
1319       nir_print_shader(nir, stderr);
1320    }
1321 }
1322 
1323 static bool
brw_nir_apply_sampler_key(nir_shader * nir,const struct brw_compiler * compiler,const struct brw_sampler_prog_key_data * key_tex)1324 brw_nir_apply_sampler_key(nir_shader *nir,
1325                           const struct brw_compiler *compiler,
1326                           const struct brw_sampler_prog_key_data *key_tex)
1327 {
1328    const struct intel_device_info *devinfo = compiler->devinfo;
1329    nir_lower_tex_options tex_options = {
1330       .lower_txd_clamp_bindless_sampler = true,
1331       .lower_txd_clamp_if_sampler_index_not_lt_16 = true,
1332       .lower_invalid_implicit_lod = true,
1333    };
1334 
1335    /* Iron Lake and prior require lowering of all rectangle textures */
1336    if (devinfo->ver < 6)
1337       tex_options.lower_rect = true;
1338 
1339    /* Prior to Broadwell, our hardware can't actually do GL_CLAMP */
1340    if (devinfo->ver < 8) {
1341       tex_options.saturate_s = key_tex->gl_clamp_mask[0];
1342       tex_options.saturate_t = key_tex->gl_clamp_mask[1];
1343       tex_options.saturate_r = key_tex->gl_clamp_mask[2];
1344    }
1345 
1346    /* Prior to Haswell, we have to lower gradients on shadow samplers */
1347    tex_options.lower_txd_shadow = devinfo->verx10 <= 70;
1348 
1349    tex_options.lower_y_uv_external = key_tex->y_uv_image_mask;
1350    tex_options.lower_y_u_v_external = key_tex->y_u_v_image_mask;
1351    tex_options.lower_yx_xuxv_external = key_tex->yx_xuxv_image_mask;
1352    tex_options.lower_xy_uxvx_external = key_tex->xy_uxvx_image_mask;
1353    tex_options.lower_ayuv_external = key_tex->ayuv_image_mask;
1354    tex_options.lower_xyuv_external = key_tex->xyuv_image_mask;
1355    tex_options.bt709_external = key_tex->bt709_mask;
1356    tex_options.bt2020_external = key_tex->bt2020_mask;
1357 
1358    /* Setup array of scaling factors for each texture. */
1359    memcpy(&tex_options.scale_factors, &key_tex->scale_factors,
1360           sizeof(tex_options.scale_factors));
1361 
1362    return nir_lower_tex(nir, &tex_options);
1363 }
1364 
1365 static unsigned
get_subgroup_size(const struct shader_info * info,unsigned max_subgroup_size)1366 get_subgroup_size(const struct shader_info *info, unsigned max_subgroup_size)
1367 {
1368    switch (info->subgroup_size) {
1369    case SUBGROUP_SIZE_API_CONSTANT:
1370       /* We have to use the global constant size. */
1371       return BRW_SUBGROUP_SIZE;
1372 
1373    case SUBGROUP_SIZE_UNIFORM:
1374       /* It has to be uniform across all invocations but can vary per stage
1375        * if we want.  This gives us a bit more freedom.
1376        *
1377        * For compute, brw_nir_apply_key is called per-dispatch-width so this
1378        * is the actual subgroup size and not a maximum.  However, we only
1379        * invoke one size of any given compute shader so it's still guaranteed
1380        * to be uniform across invocations.
1381        */
1382       return max_subgroup_size;
1383 
1384    case SUBGROUP_SIZE_VARYING:
1385       /* The subgroup size is allowed to be fully varying.  For geometry
1386        * stages, we know it's always 8 which is max_subgroup_size so we can
1387        * return that.  For compute, brw_nir_apply_key is called once per
1388        * dispatch-width so max_subgroup_size is the real subgroup size.
1389        *
1390        * For fragment, we return 0 and let it fall through to the back-end
1391        * compiler.  This means we can't optimize based on subgroup size but
1392        * that's a risk the client took when it asked for a varying subgroup
1393        * size.
1394        */
1395       return info->stage == MESA_SHADER_FRAGMENT ? 0 : max_subgroup_size;
1396 
1397    case SUBGROUP_SIZE_REQUIRE_8:
1398    case SUBGROUP_SIZE_REQUIRE_16:
1399    case SUBGROUP_SIZE_REQUIRE_32:
1400       assert(gl_shader_stage_uses_workgroup(info->stage));
1401       /* These enum values are expressly chosen to be equal to the subgroup
1402        * size that they require.
1403        */
1404       return info->subgroup_size;
1405 
1406    case SUBGROUP_SIZE_FULL_SUBGROUPS:
1407    case SUBGROUP_SIZE_REQUIRE_64:
1408    case SUBGROUP_SIZE_REQUIRE_128:
1409       break;
1410    }
1411 
1412    unreachable("Invalid subgroup size type");
1413 }
1414 
1415 void
brw_nir_apply_key(nir_shader * nir,const struct brw_compiler * compiler,const struct brw_base_prog_key * key,unsigned max_subgroup_size,bool is_scalar)1416 brw_nir_apply_key(nir_shader *nir,
1417                   const struct brw_compiler *compiler,
1418                   const struct brw_base_prog_key *key,
1419                   unsigned max_subgroup_size,
1420                   bool is_scalar)
1421 {
1422    bool progress = false;
1423 
1424    OPT(brw_nir_apply_sampler_key, compiler, &key->tex);
1425 
1426    const nir_lower_subgroups_options subgroups_options = {
1427       .subgroup_size = get_subgroup_size(&nir->info, max_subgroup_size),
1428       .ballot_bit_size = 32,
1429       .ballot_components = 1,
1430       .lower_subgroup_masks = true,
1431    };
1432    OPT(nir_lower_subgroups, &subgroups_options);
1433 
1434    if (key->limit_trig_input_range)
1435       OPT(brw_nir_limit_trig_input_range_workaround);
1436 
1437    if (progress)
1438       brw_nir_optimize(nir, compiler, is_scalar, false);
1439 }
1440 
1441 enum brw_conditional_mod
brw_cmod_for_nir_comparison(nir_op op)1442 brw_cmod_for_nir_comparison(nir_op op)
1443 {
1444    switch (op) {
1445    case nir_op_flt:
1446    case nir_op_flt32:
1447    case nir_op_ilt:
1448    case nir_op_ilt32:
1449    case nir_op_ult:
1450    case nir_op_ult32:
1451       return BRW_CONDITIONAL_L;
1452 
1453    case nir_op_fge:
1454    case nir_op_fge32:
1455    case nir_op_ige:
1456    case nir_op_ige32:
1457    case nir_op_uge:
1458    case nir_op_uge32:
1459       return BRW_CONDITIONAL_GE;
1460 
1461    case nir_op_feq:
1462    case nir_op_feq32:
1463    case nir_op_ieq:
1464    case nir_op_ieq32:
1465    case nir_op_b32all_fequal2:
1466    case nir_op_b32all_iequal2:
1467    case nir_op_b32all_fequal3:
1468    case nir_op_b32all_iequal3:
1469    case nir_op_b32all_fequal4:
1470    case nir_op_b32all_iequal4:
1471       return BRW_CONDITIONAL_Z;
1472 
1473    case nir_op_fneu:
1474    case nir_op_fneu32:
1475    case nir_op_ine:
1476    case nir_op_ine32:
1477    case nir_op_b32any_fnequal2:
1478    case nir_op_b32any_inequal2:
1479    case nir_op_b32any_fnequal3:
1480    case nir_op_b32any_inequal3:
1481    case nir_op_b32any_fnequal4:
1482    case nir_op_b32any_inequal4:
1483       return BRW_CONDITIONAL_NZ;
1484 
1485    default:
1486       unreachable("Unsupported NIR comparison op");
1487    }
1488 }
1489 
1490 uint32_t
brw_aop_for_nir_intrinsic(const nir_intrinsic_instr * atomic)1491 brw_aop_for_nir_intrinsic(const nir_intrinsic_instr *atomic)
1492 {
1493    switch (atomic->intrinsic) {
1494 #define AOP_CASE(atom) \
1495    case nir_intrinsic_image_atomic_##atom:            \
1496    case nir_intrinsic_bindless_image_atomic_##atom:   \
1497    case nir_intrinsic_ssbo_atomic_##atom:             \
1498    case nir_intrinsic_shared_atomic_##atom:           \
1499    case nir_intrinsic_global_atomic_##atom
1500 
1501    AOP_CASE(add): {
1502       unsigned src_idx;
1503       switch (atomic->intrinsic) {
1504       case nir_intrinsic_image_atomic_add:
1505       case nir_intrinsic_bindless_image_atomic_add:
1506          src_idx = 3;
1507          break;
1508       case nir_intrinsic_ssbo_atomic_add:
1509          src_idx = 2;
1510          break;
1511       case nir_intrinsic_shared_atomic_add:
1512       case nir_intrinsic_global_atomic_add:
1513          src_idx = 1;
1514          break;
1515       default:
1516          unreachable("Invalid add atomic opcode");
1517       }
1518 
1519       if (nir_src_is_const(atomic->src[src_idx])) {
1520          int64_t add_val = nir_src_as_int(atomic->src[src_idx]);
1521          if (add_val == 1)
1522             return BRW_AOP_INC;
1523          else if (add_val == -1)
1524             return BRW_AOP_DEC;
1525       }
1526       return BRW_AOP_ADD;
1527    }
1528 
1529    AOP_CASE(imin):         return BRW_AOP_IMIN;
1530    AOP_CASE(umin):         return BRW_AOP_UMIN;
1531    AOP_CASE(imax):         return BRW_AOP_IMAX;
1532    AOP_CASE(umax):         return BRW_AOP_UMAX;
1533    AOP_CASE(and):          return BRW_AOP_AND;
1534    AOP_CASE(or):           return BRW_AOP_OR;
1535    AOP_CASE(xor):          return BRW_AOP_XOR;
1536    AOP_CASE(exchange):     return BRW_AOP_MOV;
1537    AOP_CASE(comp_swap):    return BRW_AOP_CMPWR;
1538 
1539 #undef AOP_CASE
1540 #define AOP_CASE(atom) \
1541    case nir_intrinsic_ssbo_atomic_##atom:          \
1542    case nir_intrinsic_shared_atomic_##atom:        \
1543    case nir_intrinsic_global_atomic_##atom
1544 
1545    AOP_CASE(fmin):         return BRW_AOP_FMIN;
1546    AOP_CASE(fmax):         return BRW_AOP_FMAX;
1547    AOP_CASE(fcomp_swap):   return BRW_AOP_FCMPWR;
1548    AOP_CASE(fadd):         return BRW_AOP_FADD;
1549 
1550 #undef AOP_CASE
1551 
1552    default:
1553       unreachable("Unsupported NIR atomic intrinsic");
1554    }
1555 }
1556 
1557 enum brw_reg_type
brw_type_for_nir_type(const struct intel_device_info * devinfo,nir_alu_type type)1558 brw_type_for_nir_type(const struct intel_device_info *devinfo,
1559                       nir_alu_type type)
1560 {
1561    switch (type) {
1562    case nir_type_uint:
1563    case nir_type_uint32:
1564       return BRW_REGISTER_TYPE_UD;
1565    case nir_type_bool:
1566    case nir_type_int:
1567    case nir_type_bool32:
1568    case nir_type_int32:
1569       return BRW_REGISTER_TYPE_D;
1570    case nir_type_float:
1571    case nir_type_float32:
1572       return BRW_REGISTER_TYPE_F;
1573    case nir_type_float16:
1574       return BRW_REGISTER_TYPE_HF;
1575    case nir_type_float64:
1576       return BRW_REGISTER_TYPE_DF;
1577    case nir_type_int64:
1578       return devinfo->ver < 8 ? BRW_REGISTER_TYPE_DF : BRW_REGISTER_TYPE_Q;
1579    case nir_type_uint64:
1580       return devinfo->ver < 8 ? BRW_REGISTER_TYPE_DF : BRW_REGISTER_TYPE_UQ;
1581    case nir_type_int16:
1582       return BRW_REGISTER_TYPE_W;
1583    case nir_type_uint16:
1584       return BRW_REGISTER_TYPE_UW;
1585    case nir_type_int8:
1586       return BRW_REGISTER_TYPE_B;
1587    case nir_type_uint8:
1588       return BRW_REGISTER_TYPE_UB;
1589    default:
1590       unreachable("unknown type");
1591    }
1592 
1593    return BRW_REGISTER_TYPE_F;
1594 }
1595 
1596 nir_shader *
brw_nir_create_passthrough_tcs(void * mem_ctx,const struct brw_compiler * compiler,const nir_shader_compiler_options * options,const struct brw_tcs_prog_key * key)1597 brw_nir_create_passthrough_tcs(void *mem_ctx, const struct brw_compiler *compiler,
1598                                const nir_shader_compiler_options *options,
1599                                const struct brw_tcs_prog_key *key)
1600 {
1601    nir_builder b = nir_builder_init_simple_shader(MESA_SHADER_TESS_CTRL,
1602                                                   options, "passthrough TCS");
1603    ralloc_steal(mem_ctx, b.shader);
1604    nir_shader *nir = b.shader;
1605    nir_variable *var;
1606    nir_ssa_def *load;
1607    nir_ssa_def *zero = nir_imm_int(&b, 0);
1608    nir_ssa_def *invoc_id = nir_load_invocation_id(&b);
1609 
1610    nir->info.inputs_read = key->outputs_written &
1611       ~(VARYING_BIT_TESS_LEVEL_INNER | VARYING_BIT_TESS_LEVEL_OUTER);
1612    nir->info.outputs_written = key->outputs_written;
1613    nir->info.tess.tcs_vertices_out = key->input_vertices;
1614    nir->num_uniforms = 8 * sizeof(uint32_t);
1615 
1616    var = nir_variable_create(nir, nir_var_uniform, glsl_vec4_type(), "hdr_0");
1617    var->data.location = 0;
1618    var = nir_variable_create(nir, nir_var_uniform, glsl_vec4_type(), "hdr_1");
1619    var->data.location = 1;
1620 
1621    /* Write the patch URB header. */
1622    for (int i = 0; i <= 1; i++) {
1623       load = nir_load_uniform(&b, 4, 32, zero, .base = i * 4 * sizeof(uint32_t));
1624 
1625       nir_store_output(&b, load, zero,
1626                        .base = VARYING_SLOT_TESS_LEVEL_INNER - i,
1627                        .write_mask = WRITEMASK_XYZW);
1628    }
1629 
1630    /* Copy inputs to outputs. */
1631    uint64_t varyings = nir->info.inputs_read;
1632 
1633    while (varyings != 0) {
1634       const int varying = ffsll(varyings) - 1;
1635 
1636       load = nir_load_per_vertex_input(&b, 4, 32, invoc_id, zero, .base = varying);
1637 
1638       nir_store_per_vertex_output(&b, load, invoc_id, zero,
1639                                   .base = varying,
1640                                   .write_mask = WRITEMASK_XYZW);
1641 
1642       varyings &= ~BITFIELD64_BIT(varying);
1643    }
1644 
1645    nir_validate_shader(nir, "in brw_nir_create_passthrough_tcs");
1646 
1647    brw_preprocess_nir(compiler, nir, NULL);
1648 
1649    return nir;
1650 }
1651 
1652 nir_ssa_def *
brw_nir_load_global_const(nir_builder * b,nir_intrinsic_instr * load_uniform,nir_ssa_def * base_addr,unsigned off)1653 brw_nir_load_global_const(nir_builder *b, nir_intrinsic_instr *load_uniform,
1654       nir_ssa_def *base_addr, unsigned off)
1655 {
1656    assert(load_uniform->intrinsic == nir_intrinsic_load_uniform);
1657    assert(load_uniform->dest.is_ssa);
1658    assert(load_uniform->src[0].is_ssa);
1659 
1660    unsigned bit_size = load_uniform->dest.ssa.bit_size;
1661    assert(bit_size >= 8 && bit_size % 8 == 0);
1662    unsigned byte_size = bit_size / 8;
1663    nir_ssa_def *sysval;
1664 
1665    if (nir_src_is_const(load_uniform->src[0])) {
1666       uint64_t offset = off +
1667                         nir_intrinsic_base(load_uniform) +
1668                         nir_src_as_uint(load_uniform->src[0]);
1669 
1670       /* Things should be component-aligned. */
1671       assert(offset % byte_size == 0);
1672 
1673       unsigned suboffset = offset % 64;
1674       uint64_t aligned_offset = offset - suboffset;
1675 
1676       /* Load two just in case we go over a 64B boundary */
1677       nir_ssa_def *data[2];
1678       for (unsigned i = 0; i < 2; i++) {
1679          nir_ssa_def *addr = nir_iadd_imm(b, base_addr, aligned_offset + i * 64);
1680          data[i] = nir_load_global_const_block_intel(b, 16, addr,
1681                                                      nir_imm_true(b));
1682       }
1683 
1684       sysval = nir_extract_bits(b, data, 2, suboffset * 8,
1685                                 load_uniform->num_components, bit_size);
1686    } else {
1687       nir_ssa_def *offset32 =
1688          nir_iadd_imm(b, load_uniform->src[0].ssa,
1689                          off + nir_intrinsic_base(load_uniform));
1690       nir_ssa_def *addr = nir_iadd(b, base_addr, nir_u2u64(b, offset32));
1691       sysval = nir_load_global_constant(b, addr, byte_size,
1692                                         load_uniform->num_components, bit_size);
1693    }
1694 
1695    return sysval;
1696 }
1697